Briquettes for metal recovery



Oct. 1, H G w -ro BRIQUETTES FOR METAL RECOVERY Filed March 11, 1954 AIN V EN TOR. Hare! d G'eor e Z04 rrz' nyion 2,808,322 BRIQUETTES FORNIETAL RECOVERY Application March 11, 1954, Serial No. 415,650 Claims.(Cl. 75-3) This invention relates to briquettes and more particularly tobriquettes of raw materials employed in the production of metals byreduction and distillation in retorts or furnaces and the like.

In the production of alkaline earth metals, it is well known to form thestarting raw materials into briquettes for charging into the retort inwhich reduction of the raw materials and distillation of the metal takesplace. In the distillation of metals from a briquetted reduction charge,the size and shape of each individual briquette should be such that themetal vapors can easily escape from the individual briquette and alsocan easily escape from the mass of briquettes in the charge. Thebriquettes must also be of such shape that they can be easily made byavailable commercial means. Shapes and sizes of the briquettes whichsatisfy one condition do not readily satisfy the other; for example,thin cylindrical tablets will pack in the charge so that no space isavailable between the briquettes for escape of vapors.

It is an object of this invention to provide a briquette of the type setforth which is of a reduced size and of a shape which will satisfy to agreater degree than briquettes heretofore proposed the desirableconditions set forth above.

The invention will be described with reference to the accompanyingdrawing, in which Figure 1 is a perspective view of a portion of a sheetof briquettes in accordance with the invention,

Figure 2 is a perspective view of a sheet of briquettes in modifiedform, and

Figure 3 is a cross-sectional view of shown in Figure 2.

In the formation of briquettes from granules or particles of rawmaterials, it is common practice to pass such granular materials betweena pair of pressing rolls having briquette forming depressions orrecesses therein. In order to reduce the size of the formed briquettesto approximately one-half the thickness of previously producedbriquettes, in accordance with the invention, it is proposed to employpressing rolls only one of which has briquette impressions cut therein,the other roll comprising a smooth surfaced cylinder.

Referring to Figure 1, the briquettes in accordance with the inventionand produced in the manner described, are of a composite nature and maycomprise a plurality of shaped briquettes I joined together by anintegral connecting sheet or flashing 2.

Each briquette is preferably of the following dimen- 810118:

the briquettes United States Patent 0 It will be appreciated that thethickness will comprise the thickness of the briquette shape proper plusthe thickness of the sheet 2. The approximate thickness of the sheet 2is v The shape of each individual briquette may vary within wide limits.Thus, they may be of hemispherical or half-ovoid shape or their uppersurfaces maybe slightly rounded contour. It will be appreciated that arounded contour will provide minimum contact with each other whenassembled in stacked relation to each other in aretort to provide spacefor escape of vapors. A preferred shape is as shown wherein eachbriquette has a generally tetragonal or orthorhombic shape. As shownalso, and preferably, the major upper surface 3 and side surfaces 4 ofeach briquette are of slightly rounded contour. The end surfaces 5 mayalso be of rounded contour with rounded corners. Each briquette also hasone plane major surface 6 in opposed relation to the major upper surface3, such surfaced being extended as a joining flash or fin by means ofthe sheet 2.

In use, sheets of joinedbriquettes are broken up into rough pieces eachcontaining from two to five briquette shapes to produce a multiple orcomposite briquette.

This facilitates handling of the briquettes. Moreover, such a multiplebriquette has the advantage of minimum thickness so that vapors passreadily from the middle of a mass of such briquettes to its surfacesince integral gas passages are provided between the raised portionswhereby even with close packing, escape of vapors readily takes place.

The following table shows the results of a series of tests in theproduction of calcium from appropriate raw materials employing (1)individual briquettes each substantially double the size of eachindividual briquette form as herein described and of corresponding shape(designated as whole briquettes), and (2) multiple briquettes of thetype herein described and illustrated (designated as half briquettes):

Weight of Metal Recovered Briquettes Percent of Theoretieal recoveryBriquettes Improvement with "HalP briquettes Weight Halt in Lbs.

Recovuw n H W ery Percent Totals 1, 719. 1 1, 772. 1

Weight, percent improvement Recovery, percent improvement from, saidcompacted mixture having a pair of sharply surface constituting acontinuation of said plane surface.

and extending therearound.

2. A briquette as defined in claim 1, each said surface being ofrectangular shape and having an overall length and Width each notsubstantially in excess of two and one-quarter inches, and the greatestthickness between said surfaces being not substantially in excess of oneand one-half inches.

3. A multiple briquette consisting of a compacted'mixture of particlesof raw materials for recovery of metal therefrom, said briquettecomprising a sheet having one side surface thereof substantially planeand free from projections, the opposite side surface of said sheethaving thereon a plurality of spaced integral projecting portions, eachsaid portion having a m ajor surface of curved contour, the combinedthickness of said sheet and one of said projecting portions being notsubstantially in excess of one and one-half inches.

4. A multiple briquette as defined in claim 3, the number of saidenlarged portions being not more than five.

5. A briquette consisting of a compacted mixture of particles of rawmaterials for recovery of metal therefrom, said briquette comprising asheet of irregular outline having one side surface thereof substantiallyplane and free from projections, the opposite side surface of said sheethaving thereon an integral projecting portion, the combined thickness ofsaid sheet and said projecting portion being not substantially in excessof one and onehalf inches.

References Cited in the file of this patent UNITED STATES PATENTS784,850 Furukawa Mar. 14, 1905 1,073,381 Wolle Sept. 16, 1913 2,386,073Stewart Oct. 2, 1945 2,485,128 Adams Oct. 18, 1949

1. A BRIQUETTE CONSISTING OF A COMPACTED MIXTURE OF PARTICLES OF RAWMATERIALS FOR RECOVERY OF METAL THEREFROM, SAID COMPACTED MIXTURE HAVINGA PAIR OF SHARPLY DEFINED EXPOSED SURFACES EACH OF MAJOR EXTENT, ONE OFSAID MAJOR SURFACES BEING OF CURVED CONTOUR, AND THE OTHER OF SAID MAJORSURFACE BEING SUBSTANTIALLY PLANE AND IN BETWEEN ANY POINT ON SAIDSECOND SURFACE AND SAID FIRST SURFACE BEING SUBSTANTIALLY LESS THAN THEWIDTH OF SAID SECOND SURFACE, AND A FIN OF IRREGULAR OUTLINE HAVING ASURFACE CONSTITUTING A CONTINUATION OF SAID PLANE SURFACE AND EXTENDINGTHEREAROUND.